aie aie... dude, you may be a master in market... but i am sure that you aren't a tech analyst... 1 modem per line ( Dsl, cable... ) make 1 ip 2 modems, with 2 lines ( dsl, cable, fiber ) makes 2 ip... However you can't connect 2 modem on the same ground line... so by example 1 in Dsl, 1 in Cable... I hope it had helped you...
depending on the type of router you have you can throttle each computer by assigning each computer on your network an internal static IP and then setting bandwith (up and down) configurations per IP. If you have a 10mbit line (up and down) you could assign each computer to use no more than 5mbit up/down and therefore leave 50% of your max bandwidth open to the other computer. If you are paying for a retail line that can be tricky because verbage in your agreement says things like "speeds up to" so you can't really split 50/50 because you may not have 100% bandwidth at all times. Try turning off the torrenting so you don't get your computer seized and focus on trading only?
Assuming OP trades (assumption based on participation of this forum) I recommend not having a torrent running machine on the same network as trading for lots of reasons. The ultimate trading setup has dedicated broadband data connection and functions as nothing but trading - no e-mail, no news feeds, no surfing, nothing. And especially no torrent. Then another setup with its own data feed and it can do all those activities which accrue risk and consume bandwidth resources and system resources. If you're not in a position to have dedicated setup, then shutting down the torrent at a minimum, while trading, is indicated.
The way I do it is trading from a virtual machine.... ...doing only that. Has plenty of bandwidth - and high uptime
If you are using bitTorrent, go to preference in options, and select bandwidth, you can set limit on up-load speed. Like other suggest, I wouldn't run any torrent on my trading side network, there are bots to scan on your networks constantly if torrent is running. There are options with fancy routers(linux, cisco etc) which you can tweak with your network, only if you know how.
Could you please show us an example? Is possible to give higher priority to a host and lower priority to a client in a host/virtual machine setup?